THE LILTING strains of a Strauss waltz filled the room. The music waxed and waned beneath the sensitive fingers of Lincoln Fields, and through half-closed eyes he could almost see whirling figures pirouetting about the waxed floor of some luxurious salon.

Music always affected him that way. It filled his mind with dreams of sheer beauty and transformed his room into a paradise of sound. His hands flickered over the piano in the last delicious combinations of tones and then slowed reluctantly to a halt.

He sighed and for a moment remained absolutely silent as if trying to extract the last essence of beauty from the dying echoes. Then he turned and smiled faintly at the other occupant of the room.

Garth Jan smiled in turn but said nothing. Garth had a great liking for Lincoln Fields, though little understanding. They were worlds apart-literally-for Garth hailed from the giant underground cities of Mars while Fields was the product of sprawling Terrestrial New York.

"How was that, Garth, old fellow?" questioned Fields doubtfully.

Garth shook his head. He spoke in his precise, painstaking manner, "I listened attentively and can truly say that it was not unpleasant. There is a certain rhythm, a cadence of sorts, which, indeed, is rather soothing. But beautiful?

No!"

There was pity in Fields' eyes-pity almost painful in its intensity. The Martian met the gaze and understood all that it meant, yet there was no answering spark of envy. His bony giant figure remained doubled up in a chair that was too small for him and one thin leg swung leisurely back and forth.

Fields lunged out of his seat impetuously and grasped his companion by the arm.

"Here! Seat yourself on the bench."

Garth obeyed genially. "I see you want to carry out some little experiment."

"You've guessed it. I've read scientific works which tried to explain all about the difference in senseequipment between Earthman and Martian, but I never could quite grasp it all."

He tapped the notes C and F in a single octave and glanced at the Martian inquiringly.

"If there's a difference," said Garth doubtfully, "it's a very slight one. If I were listening casually, I would certainly say you had hit the same note twice."

The Earthman marvelled. "How's this?" He tapped C and G.

"I can hear the difference this time."

"Well, I suppose all they say about your people is true. You poor fellows уto have such a crude sense of hearing. You don't know what you're missing."

The Martian shrugged his shoulders fatalistically. "One misses nothing that one has never possessed."

Garth Jan broke the short silence that followed. "Do you realize that this period of history is the first in which two intelligent races have been able to communicate with each other? The comparison of sense equipment is highly interesting-and rather broadens one's views on life."

"That's right," agreed the Earthman, "though we seem to have all the advantage of the comparison. You know a Terrestrial biologist stated last month that he was amazed that a race so poorly equipped in the matter of sense-perception could develop so high a civilization as yours."

"All is relative, Lincoln. What we have is sufficient for us."

Fields felt a growing frustration within him. "But if you only knew, Garth, if you only knew what you were missing.

"You've never seen the beauties of a sunset or of dancing flelds of flowers. You can't admire the blue of the sky, the green of the grass, the yellow of ripe corn. To you the world consists of shades of dark and light." He shuddered at the thought. "You can't smell a flower or appreciate its delicate perfume. You can't even enjoy such a simple thing as a good, hearty meal. You can't taste nor smell nor see color. I pity you for your drab world."

"What you say is meaningless, Lincoln. Waste no pity on me, for I am as happy as you." He rose and reached for his cane-necessary in the greater gravitational field of Earth.

"You must not judge us with such easy superiority, you know." That seemed to be the galling aspect of the matter. "We do not boast of certain accomplishments of our race of which you know nothing."

And then, as if heartily regretting his words, a wry grimace overspread his face, and he started for he door.

FIELDS sat puzzled and thoughtful for a moment, then jumped up and ran after the Martian who was stumping his way towards the exit. He gripped Garth by the shoulder and insisted that he return.

"What did you mean by that last remark?"

The Martian turned his face away as if unable to face his questioner. "Forget it, Lincoln. That was just a moment of indiscretion when your unsolicited pity got on my nerves."

Fields gave him a sharp glance. "It's true, isn't it? It's logical that Martians possess senses Earthmen do not, but it passes the bounds of reason that your people should want to keep it secret."

"That is as it may be. But now that you've found me out through my own utter stupidity, you will perhaps agree to let it go no further?"

"Of course! I'll be as secret as the grave, though I'm darned if I can make anything of it. Tell me, of what nature is this secret sense of yours?"

Garth Jan shrugged listlessly. "How can I explain? Can you define color to me, who cannot even conceive it?"

"I'm not asking for a definition. Tell me its uses. Please," he gripped the other's shoulder, "you might as well. I have given my promise of secrecy."

The Martian sighed heavily. "It won't do you much good. Would it satisfy you to know that if you were to show me two containers, each filled with a clear liquid, I could tell you at once whether either of the two were poisonous? Or, if you were to show me a copper wire, I could tell instantly whether an electric current were passing through it, even if it were as little as a thousandth of an ampere. Or I could tell you the temperature of any substance within three degrees of the true vaalue even п if you held it as much as five yards away. Or I could-well, I've said enough."

"Is that all?" demanded Fields, with a disappointed cry.

"What more do you wish?"

"All you've described is very useful-but where is the beauty in it? Has this strange sense of yours no value to the spirit as well as to the body?"

Garth Jan made an impatient movement. "Really, Lincoln, you talk foolishly. I have given you only that for which you asked-the uses I put this sense to. I certainly didn't attempt to explain its nature. Take your color sense. As far as I can see its only use is in making certain fine distinctions which I cannot.

You can identify certain chemical solutions, for instance, by something you call color when I would be forced to run a chemical analysis. Where's the beauty in that?"

Field opened his mouth to speak but the Martian motioned him testily into silence. "I know. You're going to babble foolishness about sunsets or something.

But what do you know of beauty? Have you ever known what it was to witness the beauty of the naked copper wires when an AC current is turned on? Have you sensed the delicate loveliness of induced currents set up in a solenoid when a magnet is passed through it? Have you ever attended a Martian pogrtwem?"

Garth Jan's eyes had grown misty with the thoughts he was conjuring up, and Fields stared in utter amazement. The shoe was on the other foot now and his sense of superiority left him of a sudden.

"Every race has its own attributes," he mumbled with a fatalism that had just a trace of hypocrisy in it, "but I see no reason why you should keep it such a blasted secret. We Earthmen have kept no secrets from your race."